(CNN) -- A group of Portuguese-speaking countries plans to meet Saturday to discuss a coup that roiled the tiny nation of Guinea-Bissau, plunging it into more chaos after nearly four decades of instability.
Foreign ministers from the Community of Portuguese-Speaking Countries group will discuss the coup at a gathering in Lisbon.
Guinea-Bissau is a member of the group. The group also includes Portugal, Angola, Mozambique and Brazil.
Meanwhile, the military has called all of the country's political parties -- "without exception" -- to hold a meeting Saturday, said Daba Naualna, a spokesman for the army's chief of staff.
"The situation is normal. We are trying to find a solution," Naualna told CNN.
Regarding the Lisbon talks, Naualna said that the military is following them. "It is very far from Guinea-Bissau," he added.
Coups and coup attempts are common in Guinea-Bissau since it won its independence from Portugal in 1974.
In the latest coup, soldiers arrested the acting president and prime minister, a military spokesman said Friday, as gunfire and explosions rocked the capital of Bissau.
President Raimundo Pereira and Prime Minister Carlos Gomes Jr. were taken into custody Thursday night, sparking international condemnation.
Both leaders are well and alive, said Naualna. He said a group called the military command was behind the arrests, though it was unclear who its members are.
Leaders of the nation's armed forces have taken control of the nation to ensure stability, according to the spokesman.
"The (army chief of staff) thinks, for the sake of the country, that power cannot fall into the streets and decided to have (the military) play its part in seeking solutions with the political class to resolve this crisis," the spokesman said.
Military leaders said they have no desire to "stay in power" and asked political parties to send ideas on what to do next by Sunday, the spokesman said. A meeting will take place that day to discuss the proposals.
World leaders condemned the coup, which occurred just before the second round of a presidential election set for April 29.
The African Union, the United Nations and the United States called for a return to civilian rule and demanded the release of the leaders.
U.S. State Department spokesman Mark Toner said the United States was "deeply concerned" about the safety of residents.
"We urge all parties to put down their weapons, release government leaders immediately, and restore the legitimate civilian leadership," he said.
"We remain deeply concerned about the safety of the country's interim president, senior figures, and others who may be put in harm's way because of these actions," the White House said in a statement.
In a statement, the military command said the revolt was in response to a "secret deal" between the government and Angola.
This "deal" was drawn up to allow Angolan troops in the country to attack Guinea-Bissau's military," a communique from the group said.
This group says the president and the prime minister signed the deal and accuses the African Union, whose rotating presidency is currently held by Angola, of supporting intervention by Angolan forces.
Guinea-Bissau's history has been marked by several military coups and these conflicts have ravaged its infrastructure and economy, leaving it among the poorest in the world.
The nation's first round of voting in a presidential election was held in March, and campaigning for the second round was about to begin. The election was prompted by the death of the incumbent Malam Bacai Sanha in January after a long illness.
Residences of the prime minister and some government ministers were looted, witnesses said. Public media outlets are under the control of the army and are regularly broadcasting statements from the military, witnesses said Friday.
Angola, also a former Portuguese colony, issued a statement earlier this week stating its intention to unilaterally withdraw its troops. A number of Angolan troops are in the country to help reform the country's armed forces, Angola said.
Sanha had become president in September 2009 after the assassination of his predecessor.
Despite his coming to power in what international observers deemed a fair and peaceful election, his tenure was marked by turmoil among the country's military and political leadership.
To date, no democratically elected president of the country has served a full, five-year term.
CNN's Umaro Djau, Kim Chakanetsa and David McKenzie and contributed to this report.